Int. J. Oral Maxillofac. Surg. 2010; 39: 541–547doi:10.1016/j.ijom.2010.03.006, available online at http://www.sciencedirect.com

Clinical Paper

Orthognathic Surgery

Effectiveness ofmaxillo-mandibularadvancement in obstructivesleep apnea patients with andwithout skeletal anomalies

P. Ronchi, G. Novelli, L. Colombo, S. Valsecchi, A. Oldani, M. Zucconi, A. Paddeu:Effectiveness of maxillo-mandibular advancement in obstructive sleep apnea patientswith and without skeletal anomalies. Int. J. Oral Maxillofac. Surg. 2010; 39: 541–547.# 2010 International Association of Oral and Maxillofacial Surgeons. Published byElsevier Ltd. All rights reserved.

0901-5027/060541 + 07 $36.00/0 # 2010 Inte

rnational Association of Oral and Maxillofacial Surge

P. Ronchi1, G. Novelli1,L. Colombo1, S. Valsecchi1,A. Oldani2, M. Zucconi2, A. Paddeu3

1Maxillo-Facial Surgery Unit, Sant’AnnaHospital, Como, Italy; 2Centre for SleepMedicine, San Raffaele Hospital, Milan, Italy;3U.O. Cardiorespiratory Rehabilitation,Mariano Comense, Como, Italy

Abstract. This study evaluates the effectiveness of maxillo-mandibular advancement(MMA) in patients with obstructive sleep apnea syndrome (OSAS), even thosewithout skeletal anomalies, indicating the possibility of extending this procedure tomore patients. Two groups with different skeletal patterns were studied pre- andpost-surgery. Group 1 (11 patients) had severe or moderate OSAS and maxillo-mandibular hypoplasia and/or mandibular deformities (SNA angle 788 or less orSNA angle > 788 but with SNB < 658 and severe skeletal class II malocclusion).Group 2 (11 patients) had severe or moderate OSAS without maxillo-mandibularhypoplasia or deformity (SNA angle > 808, dental class I occlusion). Analysiscomprised: apnea hypopnea index (AHI), posterior airway space (PAS), SNA andSNB angles, Epworth sleepiness scale (ESS), body mass index (BMI), and asubjective standardized questionnaire about aesthetic appearance. All patients hadincreased PAS width and complete remission of objective and subjective OSASsymptoms evaluated by AHI and ESS. Results in both groups are comparable. Datawere analysed using t-test; p < 0.005 was statistically significant. All patients weresatisfied with the functional and aesthetic results. MMA is effective in patients withsevere or moderate OSAS, even in those without skeletal and/or occlusal anomaliesand can be considered in more patients.

Keywords: OSAS; maxillo-mandibularadvancement.

Accepted for publication 16 March 2010

The primary goal of the surgical approachto severe cases of obstructive sleep apneasyndrome (OSAS) is to resolve or signifi-cantly improve the clinical situation, thusavoiding the use of nasal-continuous posi-

tive airway pressure (N-CPAP), which isfrequently badly tolerated or refused.About 50% of patients in the USA and25% in Europe have poor compliance withventilatory therapy15.

Surgical techniques involving the softtissues, such as uvulopalatopharyngo-plasty5, hyoid suspension20, partial glos-sectomy24 and lingual suspension14 havegiven partial results, mainly in cases of

ons. Published by Elsevier Ltd. All rights reserved.

542 Ronchi et al.

medium to light severity1,18. The onlytechnique that has given good results,including in obese patients, is resectionof the base of the tongue with hyoidoepi-glottoplasty3 but it has a high incidence ofintra-operative and postoperative compli-cations and sequelae.

Surgical methods involving skeletalcomponents of the oro-maxillo-facial areahave gained ground. Initially, mandibularadvancement alone was employed16, fol-lowed by anterior-inferior mandibularosteotomy7 and, more recently, maxillo-mandibular advancement (MMA) surgeryhas been employed6,13,17,19. With MMA,all the soft-tissue structures making up thepharyngeal walls are tightened at once; thisstops them from collapsing, or reduces thisoccurrence, by acting on the suprahyoidand palatal muscles and on the lateral mus-culature of the pharynx. The tongue is alsopulled forward. The result is a significantincrease of posterior airway space (PAS)and the resolution of the syndrome in a high(95%) percentage of cases.

At first, MMA was suggested forpatients with clinical and cephalometricpatterns of mandible and maxilla retru-sion, and in a second stage of treatment,after nasal or palatal surgery without sig-nificant improvement8,19. Later studies

Table 1. Analytical results for group I.

PatientsBMI

SNA

Age Sex Pre Po

1 56 M 24.6 74 72 63 M 31 85 83 45 M 29.6 71 74 29 M 22.2 74 85 26 M 24 73 86 49 F 17.5 80 87 42 F 28.7 77 88 51 M 25 80 89 48 M 26 75 8

10 42 M 24.1 78 811 37 M 26.9 73 7

Table 2. Analytical results for group II.

PatientsBMI

SNA

Age Sex Pre Po

1 38 F 31.2 83 92 45 M 23.5 83 83 50 M 30.6 80 84 47 M 27.1 82 95 62 M 27.1 80 86 54 M 31 82 97 43 M 28 82 88 30 M 23.4 84 99 45 M 25.1 82 8

10 46 M 26 80 811 40 M 27.7 83 9

recommended the use of MMA as the firstsurgical choice in patients with severeOSAS and cranio-facial anomalies6,13,17.

Although it is logical to advance bothjaws in patients with clinical and/or cepha-lometric evidence of maxillo-mandibularhypoplasia or retrusion, the possibility ofextending indications to include othertypes of patients remains unclear, andfew studies have been published9.

Regarding the maxilla, a wideadvancement beyond the traditionalcephalometric values could compromisethe facial aesthetic. This retrospectivestudy evaluates the results obtained intwo groups of patients with abnormalor normal facial patterns, throughMMA surgery. The results are discussedand compared with reports in the litera-ture, in particular the indications andmotivations for this treatment.

Materials and methods

Between January 2003 and November2007, a retrospective study of two groupsof patients affected by severe or moderateOSAS, with different skeletal patterns,and treated by MMA was carried out.Group I included 11 patients with knownsevere or moderate OSAS, who had been

SNB PAS

st Pre Post Pre Post Pre

9 64 70 4 13 468 64 68 3 10 484 65 66 5 10 713 68 72 8 11 319 79 85 8 14 703 65 75 0 7 627 71 80 3 9 758 65 80 5 9 728 74 80 5 19 754 71 80 4 9 515 69 74 4 11 36

SNB PAS

st Pre Post Pre Post Pre

0 74 81 3 11 786 78 83 0 7 604 76 81 3 11 380 81 88 4 13 645 80 84 4 10 601 82 88 5 12 719 75 79 5 12 340 82 87 3 8 244 77 82 6 11 298 77 84 3 13 260 80 88 5 12 73

undergoing treatment with N-CPAP forsome time but had not tolerated it well,and who had clinical and cephalometricevidence of dento-facial anomalies(Table 1): SNA angle 788 or less orSNA > 788, but with SNB angle < 658and severe mandibular deformity withskeletal class II malocclusion. Group IIincluded 11 patients with known severe ormoderate OSAS, who had been under-going treatment with N-CPAP for sometime but had not tolerated it well, but whohad cephalometric, occlusal and aestheticcharacteristics within the normal range(Table 2): SNA angle > 808 and class Iocclusion. Other inclusion criteria were:apnea hypopnea index (AHI) > 20, andEpworth sleepiness scale (ESS) > 10 inboth groups.

MMA was performed in all patients, toproduce mandibular advancement, mea-sured at the incisal margin of the mandib-ular incisors, of at least 10 mm. In group I,preoperative orthodontic treatment wasperformed in 8 patients; appropriate par-tial removable prostheses were preparedfor three partially edentulous patients, toachieve a better occlusal stability in postsurgery. The initial class I occlusion wasmaintained unaltered in all patients ingroup II. In 18 patients (9 in each group)

AHI Epworth S.S. Aestheticsatisfaction

Post Pre Post

6 16 0 C9 17 2 C

18 14 1 B3 13 0 C1 16 0 C4 15 2 C

11 14 2 B10 20 2 B

7 18 1 B5 12 0 B3 13 0 C

AHI Epworth S.S. Aestheticsatisfaction

Post Pre Post

7 18 1 B12 11 1 A

4 12 2 A6 11 0 B

15 13 1 A10 12 2 A10 12 0 B

1 12 0 B10 11 3 B

1 14 0 A8 12 0 C

Maxillo-mandibular advancement in OSAS 543

Fig. 1. (a and b) Diagram showing the patterns of MMA and genioplasty.

associated advancement genioplasty wasperformed, following the techniquedescribed by PRINSELL

17 (Fig. 1a and b).Septoplasty was carried out in 15

patients (8 in group I and 7 in group II)and reduction of the inferior turbinates in 4(2 in each group). In 2 patients in group II,in whom the osteotomy gap at the maxillawas particularly wide, a graft of cortico-cancellous bone, harvested from the iliaccrest, was utilized (Table 3).

In all cases, fixation was achieved usingmicroplates at the maxilla and miniplateswith monocortical screws at the mandible.Maxillo-mandibular fixation was not usedin any cases. In group II patients, carefulremodelling of the anterior nasal spine andpyriform area was used to avoid excessiveprotrusion of cheeks and/or lips. For thesame reason, a meticulous alar cinchsuture was performed, but not a VY clo-sure of the vestibular mucosa, a linearclosure was preferred. It is known thatadvancement of superior labrale canchange from 60% to 90% in relation withthe skeletal advancement of the maxilla,depending on soft tissue management andVY closure of the mucosa2. The use of N-CPAP was abandoned from day 1 post-surgery.

Table 3. Adjunctive surgical procedures.

Group I patients 1 2

Genioplasty Yes YesSeptoplasty No YesTurbinates reduction No NoBone graft No NoGroup II patients 1 2Genioplasty Yes YesSeptoplasty Yes NoTurbinates reduction No NoBone graft No No

Clinical and instrumental examination,by polysomnography, lateral cephalogramand helical CT, in selected cases, wascarried out before surgery, immediatelypost-surgery (8–10 days) and at follow-up between 4 and 27 months after surgery.The indexes evaluated were: PAS (oncephalometric tracing), SNA and SNBangles, AHI, daytime sleepiness usingESS, and body mass index (BMI). Datawere analysed using Student’s t-test, con-sidering p < 0.005 as statistically signifi-cant.

In some cases, a 3D volumetric evalua-tion of the posterior airways was per-formed using a helical CT scan. Recentstudies have demonstrated the effective-ness of this technique to evaluate theantero-posterior and lateral dimension ofthe airways space4. These dimensionsshow a wide range of linear and volu-metric measurement in different patients,so it is difficult to define a mean minimumvalue, but a percentage increase in anindividual patient is very significant. Thisprocedure has recently become popu-lar22,25, but is limited to selected casesbecause of its high cost and the amountof radiation. In the present cases, theauthors measured the total volume of

3 4 5 6 7

No Yes Yes Yes YeYes Yes No Yes YeNo No Yes No NoNo No No No No3 4 5 6 7

Yes Yes Yes Yes YeYes Yes No No YeYes No No No YeNo Yes Yes No No

PAS between two horizontal planes(superior limit of hard palate and apexof epiglottis), pre- and postoperatively.The authors consider that PAS evaluationon the lateral cephalogram is valid, bothfrom a clinical and statistical point ofview, for a study with a fairly large num-ber of patients.

The patient’s subjective experienceswere evaluated using a standardized ques-tionnaire. They were asked to evaluate andjudge their profile and their aestheticappearance before and after surgery, withfour different degrees of judgement:unchanged (a), slightly improved (b), veryimproved (c), worse (d). Finally, theywere asked to judge their overall satisfac-tion with the treatment outcomes, andwhether they would recommend the sametreatment to other patients.

Results

In group I (Table 1) an increase in PASwas recorded, with the mean value risingfrom 4.4 (SD 2.3) to 11.1 (SD 3.2) at thepostoperative check-up (p < 0.001). Acomplete remission of subjective daytimesymptoms was achieved, evaluated byESS. The number of oxygen desaturationevents (AHI) decreased drastically in allpatients, the mean value falling from 57.9(SD 21.9) to 7 (SD 4.8) after surgery(p < 0.001). All these variations were sta-tistically significant using Student’s t-test.Regarding the aesthetic results, fivepatients reported a slight improvementand six patients a great improvement.

In group II (Table 2) an increase in PASwas recorded, with the mean value risingfrom 3.7 (SD 1.5) to 10.9 (SD 1.9) at thepostoperative check-up (p < 0.001). Evenin this group a complete remission ofsubjective symptoms was achieved, eval-uated by ESS. The number of AHIdecreased from 50.6 (SD 19.2) to 7.6(SD 4.4) after surgery (p < 0.001).Regarding the questionnaire, five patientsreported a slight improvement, fivepatients reported unchanged appearance,and one patient reported a great improve-

8 9 10 11

s Yes Yes Yes Nos Yes No Yes Yes

Yes No No NoNo No No No

8 9 10 11s No No Yes Yess Yes No Yes Yess No No No No

No No No No

544 Ronchi et al.

Fig. 2. CT scan with 3D of the airways. (a) Preoperative; (b) postoperative.

ment. In no case was a worsening of theaesthetic appearance reported.

When performed, the 3D evaluation ofPAS by helical CT scan, demonstrated ahigh percentage of increase in volume(Fig. 2a and b).

Table 4. Final results for group I.

Preoperative

PAS 4.4 (DS 2.3)AHI 57.9 (DS 20)Epworth S.S. 15.2 (DS 2.4)

Table 5. Final results for group II.

Preoperative

PAS 3.7 (DS 1.5)AHI 50.6 (DS 19.2)Epworth S.S. 12.5 (DS 2.2)

Fig. 3. (a) Preoperative profile; (b) preoperative

The results in both groups were com-parable, using Student’s t-test analysis(Tables 4 and 5). In particular, the increaseof PAS measured on cephalograms, wassimilar in both groups (252% in group Iand 294% in group II).

Postoperative p

11.1 (DS 3.2) p < 0.0017 (DS 4.8) p < 0.0010.9 (DS 0.9) p < 0.001

Postoperative p

10.9 (DS 1.9) p < 0.0017.6 (DS 4.4) p < 0.0010.9 (DS 1) p < 0.001

cephalogram AHI 51, PAS 4, SNA 788, SNB 7

Remission of symptoms was swift in allcases, and N-CPAP was abandoned imme-diately after surgery. No temporomandib-ular joint disorders were reported. Onepatient had paraesthesia of the lower lip,which persisted at 1 year post-surgery, butwas fairly well tolerated by the patient. Allthe patients were satisfied with the func-tional and aesthetic results, and wouldrecommend the same treatment to otherpatients.

All improvements were stable over timefrom the clinical and instrumental stand-points. There were no significant changesbetween the immediate postoperativecheck-up 8–10 days post-surgery, andthe long-term check-up (mean follow-upat 13 months, minimum 4 months; max-imum 27 months). At the long-term check-up, no patients had a reduction in BMI that

18, ESS 13.

Maxillo-mandibular advancement in OSAS 545

Fig. 4. (a) Postoperative profile; (b) postoperative cephalogram, AHI 5, PAS 9, SNA 848, SNB 808, ESS 0.

Fig. 5. (a) Preoperative profile; (b) preoperative cephalogram, AHI 64, PAS 4, SNA 828, SNB 818, ESS 11.

could, even partially, explain the remis-sion of symptoms.

Figures 3–6 present two significant clin-ical cases; one from each group, with theirclinical and instrumental data.

Discussion

Treatment of patients with OSAS is notalways simple. Patients who are candidatesfor surgery have severe OSAS and theprimary goal of surgery is to resolve, orat least significantly improve, the clinicalsituation. For surgery to be successful it isnecessary to determine the anatomical

causes and physiopathological mechanismsunderlying the syndrome. A number ofdifferent areas may be targeted, but it isnow generally agreed that restriction ofPAS, especially if this restriction extendsvertically, is the critical point for the patho-genesis of OSAS4,17,25. Analysis of theliterature reveals that the increase in PASafter MMA is greater than that offered byother surgical techniques such as anterior-inferior osteotomy of the mandible or hyoidor lingual suspension4,17. LI et al.10 showedthat the ‘tightening’ effect of MMA affectsthe lateral walls of the pharynx, whichcomprise the aponeuroses and muscles ofthe hypopharynx; it thus offers a stable and

significant reduction in the collapsibility ofthe hypopharynx.

The enlargement of PAS by MMA hasbeen demonstrated using helical CT scansand 3D evaluation4. Using 3D geometricalreconstruction and computational fluiddynamics simulations, it is possible topredict the likely success of treatment,and to forecast the amount of surgicalmovement necessary to create an adequateairflow22.

In patients with known severe OSAS,MMA is undoubtedly a resolutive opera-tion. Initially, MMA was employed in asecond stage of treatment, after failure ofprevious nasal and/or palatal surgery, and

546 Ronchi et al.

Fig. 6. (a) Postoperative profile; (b) postoperative cephalogram, AHI 6, PAS 13, SNA 908, SNB 888, ESS 0.

in patients with a cephalometric pattern ofcranio-facial anomalies1,8,19. This proto-col is still suggested by SCHENDEL andPOWELL

21, while HOCHBAN, MILES andPRINSELL

6,13,17 propose MMA as the firststage treatment, if necessary followed byother surgical procedures, in patients withcranio-facial anomalies. Recently, MMAhas been employed as the first treatment,with simultaneous adjunctive procedures(genioplasty, uvuloplasty, glossoplasty),but always in patients with maxillo-man-dibular retroposition or retromandibu-lism23.

The authors’ study confirms thesedata, but emphasizes that, in patientsin whom subjective symptoms are sig-nificant and with an important restrictionof PAS (measured by cephalometricsand/or helical CT scan) the primaryindication could be MMA surgery, evenin patients without dento-facial anoma-lies, because the success rate is veryhigh. Other simultaneous procedurescan be applied, such genioplasty, septo-plasty, turbinates reduction, to achieve abetter functional result.

Regarding the possibility of extendingindications of MMA to patients withoutcranio-facial anomalies and with cepha-lometric, occlusal and aesthetic patternsthat are within the normal range, theprincipal contraindication is the risk ofproducing protrusion of the jaws, espe-cially regarding the maxilla and superiorlip. In the authors’ view this risk shouldnot be overly emphasized, even in thelight of another study by LI et al.9. Theauthors think that with adequate reshav-ing of the anterior nasal spine and pyri-form area, and suitable management ofthe soft tissues during closure of surgical

access, with careful alar cinch suture,but without a VY closure, the protrusiveeffect on the soft tissues and upper lipcan be reduced. Advancement genio-plasty may also contribute to makingany protrusion of the upper lip lessapparent. Thus, also for these patients,MMA may provide a primary surgicalsolution.

The treatment of OSAS and the choiceof MMA as primary treatment do notdepend only on cephalometric measure-ments, but mainly on the severity of OSASand restriction of PAS. The present studyand the comparison of the two groups ofpatients demonstrate that the functionalresults are comparable.

Recent studies have also demonstratedthat MMA is the most effective operationfor treatment of OSAS, and the quality oflife of the patients treated with this pro-cedure is greatly increased12.

The authors think that a good groundingin, and experience in the field of, orthog-nathic surgery is necessary to treat thesepatients, even if the use of prebent advance-ment plates can facilitate the procedure, assuggested by LYE et al.11. The OSAS patientpresents a complex case from diagnosticapproach to the immediate pre- and post-operative periods21. In conclusion, the indi-cations for MMA in OSAS patients can beextended significantly to patients withoutskeletal anomalies, because this procedureconstitutes an effective, reliable and versa-tile surgical solution and may be applied toa wide range of patients with severe ormoderate OSAS.

Funding

None.

Competing interests

None declared.

Ethical approval

Not required.

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Address:Giorgio NovelliViale Cesare Battisti 6620052 MonzaMilanoItalyTel.: +39 347 2746029.E-mail: g.novelli@hsgerardo.org